Aphasia strikes approximately one in 250 Americans. The reduced ability to communicate with language represents, in most cases, a catastrophic loss of self-sufficiency and a source of profound social isolation. No treatment for aphasia reported to date has reliably brought about changes in language production that migrate from highly constrained laboratory tasks such as single picture description to more challenging and socially functional tasks such as the production of entire narratives. The current climate in health care limits access to speech therapy, and thus it is imperative to develop approaches to treatment which allow patients to supplement 1:1 clinical treatment with intensive independent home practice. We have developed two computer programs to address the need for effective aphasia treatments that can be used semi-independently. One is a communication system (CS), which allows aphasic users to record spoken sentences a single word or phrase at a time, to replay these words or phrases, and to build them into sentences and narratives by manipulating visual icons on a computer screen. The other program is a language therapy system (TS) incorporating speech recognition and natural language understanding technology, which allows the computer to 'understand' the patient's spoken sentence and to provide feedback about whether it correctly describes a picture on the screen. This allows independent home practice of spoken language. The goals of this project are: (1) to replicate pilot results showing measurably more structured language production by aphasic patients using the CS, and to link these effects to characteristics of subjects' language processing impairments (Exp. 1); (2) to assess the impact of enhancing the CS with word-finding support for more severely impaired patients (Exp. 2); (3) to replicate the positive outcomes in pilot studies which used the TS and CS to improve aphasic patients' spoken language production, and to use the TS to train subjects on grammatical structures that provide tests of specific hypotheses about the impact of impaired short term memory on aphasic production (Exp. 3); and (4) to use data automatically collected by the CS to investigate the nature of the underlying disruption and to motivate the most effective approaches to remediation (Exp. 4). Information obtained from these studies will provide a basis for the further development of novel, theoretically motivated approaches to aphasia treatment.